Halogenations of 3-aryl-1H-pyrazol-5-amines

  1. Jing He,
  2. Yueting Wei,
  3. Yijiao Feng,
  4. Chuntian Li,
  5. Bin Dai and
  6. Ping LiuORCID Logo

Submitting author affiliation: Shihezi University, Shihezi, China

Beilstein Arch. 2021, 202166. https://doi.org/10.3762/bxiv.2021.66.v1

Published 24 Sep 2021

  • Preprint


A direct C-H halogenation of 3-aryl-1H-pyrazol-5-amines with NXS (X = Br, I, Cl) as cheap and safe halogenating reagents at room temperature has been developed. This transformation provides an effective metal-free protocol towards the synthesis of novel 4-halogenated pyrazole derivatives with moderate to excellent yields. The method represents simple and mild reaction conditions, broad substrate scope as well as gram-scale synthesis. The utility of this procedure is established by further transformations of the 4-halogenated products. Mechanism studies show that DMSO plays a dual role of catalyst and solvent.

Keywords: Halogenation; Metal-free; Pyrazol-5-amine; Synthesis; 4-halogenopyrazole

Supporting Information

Format: PDF Size: 116.7 KB   Download
Format: PDF Size: 130.1 KB   Download
Format: PDF Size: 1.3 MB   Download

How to Cite

When a peer-reviewed version of this preprint is available, this information will be updated in the information box above. If no peer-reviewed version is available, please cite this preprint using the following information:

He, J.; Wei, Y.; Feng, Y.; Li, C.; Dai, B.; Liu, P. Beilstein Arch. 2021, 202166. doi:10.3762/bxiv.2021.66.v1

Download Citation
Download RIS (Reference Manager) Download BIB (BIBTEX)

© 2021 He et al.; licensee Beilstein-Institut.
This is an open access work under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0). Please note that the reuse, redistribution and reproduction in particular requires that the author(s) and source are credited and that individual graphics may be subject to special legal provisions.
The license is subject to the Beilstein Archives terms and conditions: (https://www.beilstein-archives.org/xiv/terms)

Other Beilstein-Institut Open Science Activities